Method and machine for grooving shaving gears



Jan. 23, 1940. E w 5 ET AL 2,187,992

METHOD AND MACHINE FOR GROOVING SHAVING GEARS Filed Nov. 25, 1936 2 Sheets-Sheet l Jan. 23, 1940. E. WILDHABER ET AL METHOD AND MACHINE FOR GROOVING SHAVING GEARS Filed Nov. 25, 1936 2 Sheets-Sheet 2 Imnentors Gttorneg 10 performed by meshing the gear to be shaved with crating the operation of grooving one side of the 10,

Patented Jan, 23, 1940 Q e v i I I METHOD AND MACHINE FOR GROOVING' SHAVING GEARS Ernest Wildhaber, Irondequoit, and Allan H. Candee and Winfred A. Witham, Rochester, N. Y., assignors to Gleason Works, Rochester,-

N. Y., a corporation of New York UNITED STATES rainstorm-c Application November 25, 1936, Serial No. 112,739 22 Claims. (01. 90-151) The demand-for quieter and quieter gears has spiral bevel gear'cutting machine of standard. resulted in the past few years in ever-increasing form as modified to practice the present. invenuse of the so-called shaving method as an auxtion, part ofthe machine being broken away and. iliary finishing operation in the-production of shown insectiom' I. I V f 5 high quality gears such asare intended for use, Figs. .2 and 3 are detail views taken atright 5 M for'instance, in automotive drives. angles to one another and showing parts of the i 'In gear shaving, the toolemployed is of gear mechanism for adjusting the cutter axially in form and its teeth are gashed or grooved to the machine shown; g provide cutting edges. The shaving operation is Fi 4 is a. diagrammatic sectional view i1lu'sthe shaving gear and operating thetwo together teeth o 8 Sp a bevel hVP d Shaving a as though they were a pair of meshing gears. In with cutteroonstructed according to one emsome-instances, the gear to be shaved and the bodiment of this invention; Y shaving gear are so meshed that a relative sliding Fig. is a view I showing the grooving of the motion is produced between them as they operate Opp e de Of e e h 0f the Shaving s 15 i together. In other instances, the relative Sliding with a cutter of slightly modifiedform; v movement is efiected as an addedmotion. In g. 6 o s-Sec an ed scale still other instances, the work and shaving gear Of'a s av g g after the grooving Opera-tier! U have a pure rolling motion in mesh and there is iscomp eted'; a d

no relative sliding. Fig. '7 is a side elevation of one'blade of a cutter 20 The present invention relates to a machine such as-might-be employed in the grooving and method for grooving shaving gears and also process. v 5 I i to tools employable in the grooving of shaving In grooving-shaving gears by the present in gears. In particular, the invention relates to the Ve t a Cutting 11001? s preferably p y grooving of shaving'gears whose-cutting edges are which has'a cutti edge O y a plurality 26 formed by grooves extending longitudinally in of alternate grooves and lands. Such a tool is. f thesides of the teeth. More especially, the incapa l f fo m n i l ne ly'ap l ty f ventionrelates to the production of longitudinalg ooves and la ds on the side of a tooth of the ly curved tooth shaving sears which are of shaving gear-as it is moved across the face of 1 30 tapered gear form and of the non-generated or the gear-from one endof the tooth to theother. 30 Formate type and intended for finishing spiral grooving: p a bevel a d ypo'id" Shav bevel and hypoid gears. In a still more specific gears e Cutting $001 P bly s the form aspect, the invention relates to the groovin of of aface-mill having a plurality of cutting blades shaving gears of the type covered by the pendwhose side faces arepro-videdwith a plurality of :25 ing" United States application of Winfred A. r ves spa t di d i n f h ight f "the as Witham, Serial No. 61,237, filed January 28, 1936. lad The grooves are produced in the side sur- One purpose of the'present invention is to proface o t S gear y imparting a 'Cllttihg vide a very fast but relatively cheap and simple motion o h gI'OOViHg i001v d e g the tool methodof grooving shaving gears of the characsidewise into the tooth surface.

4o ter described. 5 The sidewise or lateral feed movement may 40 .Another object of the invention is to provide be effe ed in hysuitable manner. In grooving simple, but eilicient apparatus for carrying out a Spiral bevel h pfl dsh'avinggear it is possible, Said methmihowever, to'llse a standard Spiral Bevel Gear A further object of the invention is to provide Grimm-ailing Machine w th y a sli modificaa method for grooving shaving gears which may tion thereof to practice the present invention and 4 be performed upon existing gear cutting-ma such a machine has been illustrated in the ac chinery with but slight modification thereof. comp ing win s v a v n s ar Still another object of the invention is to pro n is machine, the v utting tool is videa highly efiicient form of cutting tool for the mounted-0h the Cutter pi 0f e ch e and I 5 grooving operation. v a 1 a finish-cut spiral bevel or hypoid gear is mount- 5 Other objects of the invention will be apparent ed on the work spindle of the machine. The hereinafter from the specification and from the work may be rotated. to feed the worklaterally recital of the appended claims. into the cutter, but preferably the work is held In the drawings: stationary von its axis during cutting'andthe Fig. 1 is a fragmentary side elevation of a lateral feedis produced by rotation of the cradle '55 upon which the cutter is mounted. The rotary movement of the cradle produces a lateral feed movement between the grooving cutter and the work in a direction substantially perpendicular to a side surface of a tooth of the work.

After the grooves have been cut to the required depth in a side of a tooth of the work, the direction of'rotation of the cradle is reversed to withdraw the grooving cutter sidewise from the cut and at the end of the reverse movement of the cradle, the work is withdrawn relatively from engagement with the cutter and then the work is indexed to bring a new tooth surface of the work into position to be grooved. The grooving cutter is then moved back into engagement with the work and the grooving cycle begins anew.

In the grooving of opposite side tooth surfaces of the work, the sidewise feed between the grooving cutter and the work is in opposite directions.

A cutter may be used that has opposite side- .cutting edges and it may be readjusted relative to the workbetween the grooving of opposite sides of the teeth of the work or different cutters may be used for the grooving of the opposite sides of theteeth.

Preferably between the grooving of successive corresponding sides of the teeth of the work, the grooving cutter is shifted a slight amount axially so that the grooves on the corresponding sides of successive teeth of the tool gear may be displaced slightly and progressively with reference to one another. A shaving gear grooved in this manner will produce a smoother shaved surface on a gear being shaved.

The grooving cutter may have the grooves in the sides of its cutting blades formed in any suitable manner. Preferably, the grooves are cut into the sides of the cutting blades so that the sides of the grooves will extend in a direction parallel to the direction of feed of the tool, that is,

for a face-mill type of grooving cutter, in a direction perpendicular to the axis of the cutter. With this construction, grooves may be cut into the shaving gear whose sides are perpendicular to the side surfaces of the shaving gear. A shaving gear with grooves so formed will have a keen cutting action.

Where the feed of the grooving cutter into the side surface of the teeth of the shaving gear is produced by rotation of a cradle upon which the cutter is mounted, it is preferable to maintain the side cutting edge of the grooving cutter parallel to the axis of the cradle so that the rotational movement of the cradle will produce a lateral feed of the cutter in a direction substantially perpendicular to the side surface of the tooth of the work. This can be achieved readily with a grooving tool whose cutting blades have active side'surfaces of zero pressure angle and for that reason such a tool is employed where possible. It is entirely practical to use blades of zero pressure angle for cutting one side of the teeth of a shaving gear, the concave side surfaces of a spiral bevel or hypoid gear for instance, but it is not always feasible to use a cutter having cutting edges of zero pressure angle for grooving the opposite side of the teeth of the work, the convex side surfaces of a longitudinally curved tooth shaving gear for instance. This is because where a tool of zero pressure angle is used, the work must be adjusted angularly into the grooving cutter by the amount of the pressure angle of its tooth surfaces. On the convex sides of the teeth of spiral bevel or hypoid gears in most instances,that is, except where the. work diameter is small, this would be impossible without interference between the work and the grooving cutter. For grooving one side of the teeth of a shaving gear, then, the convex side of a longitudinally curved tooth shaving gear, for instance, a grooving cutter having blades whose active side surfaces are of positive pressure angle will ordinarily be .required. In order that the feed of the cutter into the sides of the tooth surfaces of the work may be as nearly as possible in a direction perpendicular to the sides of the teeth of the work, however, it is desirable tokeep the pressure angle of the sides of the blades of the grooving tool as small as possible.

The grooves in the side surfaces of the blades of the grooving cutter may be of any desired shape. A preferable construction is to provide the blades with grooves having parallel sides and it is preferred to have these grooves arranged so that the sides of the grooves lie in planes perpendicular to the axis of the cutter, that is, parallel to the direction of cut. Such a grooving cutter will cut grooves in the side. surfaces of the shaving gear which will have parallel sides perpendicular to or approximately perpendicular to the sides of the shaving gear. It is also within the scope of the invention to make the grooves in the grooving cutter blades of I other shape. Thus, the grooves might be made V-shaped or dove-tailed in shape, that is, with the sides of the grooves undercut, and, where the grooving cutter has blades whose active sides are of positive pressure angle, the grooves in said sides of the blades may extend either perpendicular to the axis of the cutter or at any desired angle thereto.

Reference will now be had to the drawings for a more detailed description of the invention. Here, I have shown how a gear cutting machine of the type covered by U. S. Patent No. 1,724,241 of August 13, 1929, may be modified to practice the present invention in the grooving of a longitudinally curved, tooth shaving gear of spiral bevel or hypoid gear form having non-generated side tooth surfaces.

The shaving gear blank is designated at G. It is a previously finish-cut non-generated spiral bevel or hypoid gear having longitudinally curved teeth of straight profile shape. The shaving gear blank is secured to the work spindle of the machine in the usual or in any suitable manner. The work spindle is journaled in the usual manner upon the work head H! of the machine. The work head has the usual linear and angular adjustments on the swinging base 'H of the machine for adjusting the work into operative position. The means for effecting these adjustments have not been shown but may correspond to those illustrated in my prior patent above mentioned. Ordinarily, it is not required to offset the axis of the 'work from the axis of the cradle to groove shaving gears by the process of the present invention and hence the vertical adjustment of the work head described in the prior patent above mentioned, may be omitted in a machine for practicing the present invention and, hence, a work head without adjustmentfor offset of the work spindle is illustrated in the accompanying drawings. Such a work head corresponds to the type ordinarily employed on Spiral Bevel a ter spindle.

- is made.

' frame 41 of the machine.

'Ihe cutter spindle is driven from a motor l6 through bevel gearing l1, iii, a shaft I9 to which the bevel gear I8 is secured, a pair of spur gears (not shown) which connect the shaft I9 with a parallel shaft (not shown), a bevel gear (not shown) carried by the latter shaft, a bevel gear 20 which is driven by the last named bevel gear, the shaft 2! to which the bevel gear 26 1s secured, the spur pinion 22 which is integral with the shaft and the internal gear 23 which is secured to the enlarged end face or seat portion 24 of the cutter spindle. All of the parts mentioned are mounted upon the saddle [5.

The saddle l5, as will be described more fully hereinafter, is mounted upon a plate 26 for stepby-ste'p movement in a direction axial of the cut- The saddle is guided in this movement by a way 25which is formed upon the plate 2 6 and the saddle is held upon the plate by the gib 21 which is secured to the plate by screws 28.

The plate 25, as described inthe patent above mentioned, is angularly adjustable upon a slide 30 about an axis perpendicular to the axis of the cutter spindle. This adjustment is ordinarily not used in practicing the present invention. The slide 30 is adjustable vertically upon a column 32, through rotation of the screw shaft 33 which is rotatably mounted in the column and threads into a nut (not shown) which is secured to the 7 back of the slide 30.

The column 32 is adjustable angularly upon a plate 35 about an axis at right angles to the axis about which the adjustment of the plate 26 This adjustment, too, is ordinarily not employed in practicing the present invention. The plate 35 is adjustable laterally upon the cradle 36 by a screw shaft 31 which is journaled in the plate 35 and threads into a nut (not shown) which is secured to the upper face of the cradle. The column 32 and plate 35 are secured to the cradle after adjustment by T-bolts 38.

The various adjustments referred to and the' means for making the same are described more fully in my prior patent above referred to and reference may be had to that patent for a more detailed description of the same.

The cradle is formed, as in the machine of my prior patent, with arcuate guide surfaces 40 which seat on ways ll formed on the base or The cradle has an oscillatory movement, as in the machine of my prior patent, and this movement is produced by a worm 43 which meshes with worm wheel M which is secured by screws 45 to the cradle.

' Thedrive to the cradle may be thesame as in my prior patent. This drive is, however, disconnected from the drive to the work spindle in the preferred practice of the present invention so that during the actual cutting of the grooves in the side surfaces of the teeth of the shaving gear, the work spindle does not have a rotary motion but remains stationary. The only drive to the work spindle is that employed for indexing the work from tooth to tooth. The indexing mechanism may be similar to that employed in the machine of my prior patent and only the final members of the indexing drive are illustrated in the accompanying drawings, namely, theworm se and the worm wheel 51.

The grooving cutter may have blades. with a single cutting land or rib, but preferably the blades of the grooving cutter are grooved to providea plurality of cutting lands, as shown in the cutteruillustrated in the drawings, so that the.

whole side surface of a tooth of the work can be grooved at one time. The-latter'type of cutter is shown in the drawings. This cutter has cutting blades B which have parallel grooves 55 in their side faces that extend from the front to the back of the blades, as illustrated inFig. '7, and are spaced from one another on the blades in the direction of the heig ht of the blades.

The grooves are preferably cut into the sides of the blades so that they extend in a direction perpendicular to the axis Act the cutter and-are preferably made, as shown in Figs. 4 and 5, so that they have parallel sides.

It is possible to cut'gro'oves in only one side of the teeth of the shaving gear at a time. In 4, I have shown a cutter whose blades have grooves in their outside surfaces for' cutting grooves in-the concave sides of the teethof the work. In Fig." 5,- I have shown a cutter Cfor grooving the convex sides of the teeth of the work. This cutter'has grooves formed on the insidesuriaces of the blades. 11' the same cutter is to be used for grooving both sides of the teeth of the work, both sides'of its blades should be grooved. Only one side of theteeth of the work can be grooved at a time and the cutter must readjusted relative to the work to groove the opposite sides of the teeth of the work.

Preferably, diiferent cutters are employed-for grooving the opposite sides of the teeth. of the work. Where separate cutters orseparate blades are used for grooving the opposite sides of the teeth of the work-theinactlve sides of the blades may be left smooth,,as shownin thecase of the inactive sides of the blades illustrated in Figs; eland5. =To groove a shaving gear of spiral bevel or hypoid form on a machine built to 'practice'the present invention, the work and grooving tool are adjusted relative to one another as in setting up a machine to cut a spiral bevel or'hypoid gear. a f Fig. 4 illustrates the relative positions ofa gear, G, which is to be grooved; and acutter- C of preferred form for the grooving of' the con cave sides of the teeth of such gear G. The tool C shown in Fig.- 4 has blades 66 which have grooved outside surfaces which are of zero pres sure angle, that is, which are parallel to the axis A of the cutter.; The gear G musaaccordingly, be adjusted relative to the cutter in accordance with the pressureangle a of the concave side's 6| of the teeth 62. This an iuar adjustment cache til effected in the usual manner by lateral and vei ticaladjustme'nt of the cutter and by slight modificaticn in the root angle setting of the Work.

In-Fig. 5, I have shown the work gear G "ad'- justed relative to the cutter C which is to groove the convex sides 63 of the teeth 62 of the gear; Here a cutter C is used whose cutting edges have a slight positive pressure'a'n'gle a.

In the operation of the machine illustrated, the

cutter rotates continuously on its axis; the workv is fed into operative relationwith the cutter by operation of the feed cam ill which is connected clears the side of the teeth, the work is withdrawn from operative position by operation of thefeed cam and then the work is indexed. Then the cycle begins anew. During cutting, the work is held stationary as above described.

Figs. 4 and 5 illustrate diagrammatically how oscillatory motion of the cradle operates to produce the sidewisefeed and withdrawal movementsof the tool with reference to the work. denotes the axis of the cradle. It will be noted that the axis of the cutter is parallel to the axis of the cradle, but is offset therefrom, that is, it is eccentric to the axis of the cradle. Hence, as the rotating cutter is swung about the axis of the cradle, the axis A or A of the cutter will travel on a circle whose center lies on the axis 15 of the cradle. Thus, the cutter is moved bodily toward and into the sides of a tooth of the stationary work as it is swung in one direction and is withdrawn bodily away from the side of the tooth as it is swung in the opposite directionby the oscillatory movement of the cradle. Through the operation of the machine, grooves ll are cut in the concave-sides 6| of the teeth 62 of .the shaving gear, as shown in Fig. 6 and grooves 13 may be cut in the convex sides 53 of the teeth. a

The direction of lateral feed movement of the cradle for the cutting of the convex side of the teeth of the shaving gear is reversed with reference to the direction of lateral feed movement of the cradle for cutting the concave sides of the teeth. Thus, as indicated in Fig. 4, the cradle is swung about its axis l5 to move in the direction denoted by the arrow 11 to feed the cutter C sidewise into the concave sides of the teeth of the work G and is withdrawn by swinging the cradle back in the opposite direction as denoted by the arrow in 18, while in the cutting of the convex sides of the teeth of the work, the lateral feed movement is in the direction denoted by the arrow 18 in Fig. 5 and the withdrawal movement is in the direction of the arrow 11'.

As will be clear from Fig. 5, if the work gear Gis of large diameter, it would interfere with the cutter C if the work were adjusted angularly to the pressure angle of its teeth. Accordingly, for the grooving of the convex sides of theteeth of a shaving gear, it is desirable to use a cutter, such as shown in Fig. 5, having cutter blades 65 whose inside surfaces have a slight pressure angle a. This pressure angle should be kept as low as possible so that the grooves and lands on the inside surfaces of the blades may cut as nearly as possible in a directionperpendicular to the convex sides 63 of the gear teeth in their lateral in-feed movement.

It is desirable, as pointed out in the copending application of Witham above mentioned, to have the grooves in corresponding sides of a shaving gear staggered or displaced with reference to one another so that the cuts made by one tooth of the shaving gear are not merely repeated by another tooth of the shaving gear and a smoother finish may be produced on the sides of the gear by-the shaving. The machine illustrated in the drawings of the present application is provided with a mechanism for automatically shifting the grooving cutter axially between cutting of the corresponding sides of successive teeth of the work so as to produce this desired displacement of the grooves on corresponding sides of successive teeth of the shaving gear. This mechanism will now be described.

, above stated, the saddle I5 is mounted on the plate for movement axially of the cutter spindle. Secured to the plate 26 by screws 80 is a box or housing 8| in which there is journaled a screw shaft 82 which threads into a nut 83 that is integral with a cover-plate 84. The cover-plate 84 closes the bore in the saddle in which the cutter spindle and its bearings are mounted and the cover-plate is secured in position by screws not shown. The screw shaft 82 is rotated step by step, being advanced or withdrawn, each time when the work is indexed, thus advancing or withdrawing the cutter axially so that the positions of the cutter, during the grooving of corresponding sides of successive teeth of the work, are displaced axially from one another.

The mechanism for intermittently rotating the screw shaft 82 comprises a solenoid 85, the corebar 86 of which is connected by a link 81 with a bell crank lever 88. The lever 88 is oscillatably mounted upon a shaft 89 which is journaled, in the box 8| parallel to the screw shaft 82.

The bell crank lever 88 carries a pawl 98 which is pivotally mounted upon the lever by means of the pin 9|. The pawl is adapted to engage the teeth of a ratchet-wheel 92 which is keyed to the shaft 89. The pawl is held in engagement with the teeth of the ratchet wheel by a coiled-spring 84 that may be disengaged therefrom by rotating the cam-member 95 about its pivot pin 98. The cam-member is adapted to engage the tail of the pawl.

As will be seen, each time that the solenoid 85 is energized, the core-bar 85 is moved'to the left from the position shown in Fig. 3, thus oscillating the crank 88 and causing the pawl 90 to advance the ratchet wheel. There is a spur gear 98 mounted on the shaft 89 and having a splined connection thereto. This spur gear meshes with a spur pinion 99 which is secured to an idler-shaft I80 that is journaled in a quadrant arm M2. The arm I02 is adjustably mounted upon a box 8| by means of a bolt I03 which passes through an elongated slot I04 in the arm.

There is a spur gear I05 secured on the idler shaft m8 and this spur gear meshes with a spur gear I86 which has a splined connection with the screw shaft 82.

Thus, when the solenoid 85 is energized, rotation is imparted to the screw shaft 82.

Any suitable means may be employed for energizing the solenoid once for each cycle of operation of the machine. In the machine illustrated, there is a lug H0 adjustably secured by a T-bolt Ill in a circular slot H6 in one face of the feed cam Ill. The feed cam is geared to make one revolution for each feed and withdrawal movement of the work, that is, for each cycle of operation of the machine. There is a lever H2 pivotally mounted at H3 on the base of the machine. This lever carries a roller H4 in position to be engaged by the lug Illlas the lug is carried around by the rotation of the cam 18.

A lever H5 is also secured to the shaft H3. This lever is arranged so that when it is rocked clockwise it operates a switch H! that is electrically connected by means of the line H8 with the solenoid 85. The switch H1 is a normally open switch.

The shaft H3 may also carry the lever 120 for operating the automatic stopping mechanism 122 of the machine. This, however, forms no part'of the present invention. The switch H7 may be secured to one side of the 'aut' matic stopping mechanism, as shown.

The solenoid 85 is so mounted that the corebar 86 is vertical and drops 'downby gravity when the solenoidis de-energized.

With the mechanism described, it will be seen that the solenoid is energized once for each cycle of operation of the machine and thelug I It may be so adjusted on the cam 70 that energization of the solenoid takes place in the indexing interval. When the solenoid is energized, the screw shaft 82 is rotated to advance or'withdraw the cutter axially, Thus the cutter-will have a different position when cutting successive 'corresponding toothsides of the work and so the grooves formed in successive corresponding sides of the teeth of the work will be displaced depthwise with relation to one another. 7

The direction of rotation of the screw shaft depends upon the gearing employed between the ratchet wheel 92 and the screw shaft and upon the hand of the screw thread. In Fig. 6, the

grooves in successive teeth are displaced relative to one another toward the bottoms of the tooth slots. 62' designates the first tooth cut, 62 the second tooth and 63 the third tooth out. It will be noted that the grooves in corresponding sides of these teeth are successively displacedon the successive teeth toward the bottoms of the tooth spaces. v

The screw shaft 82 maybe adjusted to 'position the cutter at correct depth'prior to a cutting operation by rotation of the shaft itself by a suitable wrench and for this purpose-the A friction brake comprising a spring-pressed 1 plunger I26 of some suitable friction material serves to hold the ratchet wheel 92 against the backward movement. This, plunger is housed in a sleeve l2! that is adjustably threaded into the box 8!. 3 Due to the displacement of the cutter between grooving of successive teeth, the grooves. inthe successive teeth are arranged ina helix. If the displacement is continuous for the cutting of the grooves in all of the teeth, then corresponding grooves of the teeth will bearranged in. a single lead. If the cutter is readjusted axially after the cutting of a certain number. of teeth, then corresponding grooves of the teeth will be arranged in several leads crthrea'ds. I

In the drawings, the grooving cutters have been shown as provided with blades which haveparallel sided grooves that extend in a direction perpendicular to the axis of the. cutter. .It will be understood, however, that the blades might be provided with grooves which areparallel sided but which are inclined to the axis of the cutter if the proper direction of relative feed is used. It is also to be understood thatv the grooves might be of V-shape and extend either parallel to the axis of the cutter or inclined thereto.

blades. Other modifications will readily suggest themselves to those skilled in this art. I

While the invention has been described in connection with a machine, process, and tools for cutting grooves inthe side faces of spiral bevel appended. claims. I t

and hypoid shaving gears, it will be understood that broadly this invention is applicable. also to the grooving of other typesof shavinggears.

Grooves in straight bevel or. spur gear shaving tools might be produced, for instance, with plan ing tools having grooved side faces which are fed laterally into the sides of the teeth of the shav ing gear. For straight bevel gears, the lateral feed movement might be produced as in the'm'a- I ill chine herein described, namely, by Jrotationof the cradle upon which the planing tool is mounted while the work is held stationary. This'op era tion. can be performed upon a standard-straight bevel gear generating machine by disconnection art. The present application is intended to cover any adaptations, uses, or embodiments of'the invention will be apparent to those skilled in the present invention following, in' general, the prinpartures from the present disclosure as come within known or customary practice in the gear I art and as maybe applied to the essential 'features hereinbefore setforthandi'as fall within the scope of the invention or 'thelimits of the Having thus described .our claim is: h 1'. The method of grooving va shaving gear which comprises employing a cutting tool which has aside surface-that is provided with a pluinvention, what we rality of grooves spacedin the direction of active.

heightof the tool and a serrated side cutting edge formed at the juncture of said side surface and the front faceof thetool, engaging said tool with the gear so that it extends into'a-tooth space of the gear, and moving said tool longitudinally of the tooth space while producing a relative sidewise feed movement between the tool and gear to. fe'ed'the tool sidewise into one side of the tooth space to cut simultaneously a plurality of grooves therein. 7 i p y 2. The method of producing'a shaving gear which comprises employing. a cutting .tool' that has a serrated side surface and a side 'cuttihg edge formed at the juncture of said'side surface and the front face of the tool, engaging sa sm ciples of the invention and including suchjdewith a gear so that it extends into a-tooth space of thegea'r and moving-said tool longitudinallyof the tooth space while holding the gear stationary and producing a relative feed movement between the tool and gear about an axis inclined.

to the axis of thegear and 'paral'leltothe'fl'de scribed side surface of the'tool to feed the tool laterally into-one side surface ofthe tooth fspace to cut simultaneously a plurality" of grooves therein. v M I 3. The method'of producing'a shaving gear which'comprises grooving each tooth of the gear by moving a grooving toollongitudinallyflacross aside of -a tooth while producing a relative feed movement between the tool and gear side' wise' of the gear'tooth, indexing the gearperiodically and adjusting the tool between 'thelgrooving of'corresponding'sides ofdifferent teeth of the gear so that the grooves produced onfsuccessive teeth will be displaced progressively relative to one another-in. the direction of depth'of the teeth of the gear.

e. The method of producing a shaving gear which comprises employing a. rihbedicauttingtool .having'a serrated cuttingedge of .zero pressure angle, adjusting a previously formed gear into engagement with the tool so that a side surface of atooth of the gear is parallel to the edges of the cutting ribs of the tool, moving the tool across the side of the tooth from one end thereof to the other, and producing relative rotary movement between the tool and gear about an axis parallel to the described side of the tool to feed thetool laterally into the gear.

5. The method of producing a shavinggear whichcomprises employing a ribbed cutting tool having a serrated cutting edge of zero pressure angle, adjusting a previously formed gear relative to the tool so that a side of a tooth of the gear is parallel to the edges of the cutting ribs, moving the tool along the side of the tooth of the gear from one end thereof to the other while producing a relative rotary movement alternately in opposite directions between the tool and gear about an axis parallel to said side of the tool to feed the tool laterally into the side of the gear tooth, indexing the gear periodically, and

adjusting the tool in the direction of said axis tool and the gear laterally into a side of a tooth of the gear.

7. The method of producing a shaving gear which comprises employing a face-mill cutting tool having blades each of which has a ribbed side surface and a side cutting edge formed at the juncture of said side surface with the front face of the blade, and rotating said tool in engagement with a gear while producing a relative feed movement between the tool and gear about an axis parallel to the tool axis.

8. The method of producing a shaving gear which comprises employing a rotary face-mill cutting tool having a ribbed side surface which is parallel to the axis of the tool and a side cutting edge formed at the juncture of said side surface with the front face of the tool, adjusting a previously tocthed gear so that a side surface of a tooth of the gear is parallel to the axis of the tool, moving the tool across the side of the tooth from one end thereof to the other, and producing a relative lateral feed movement between the tool and gear in a direction perpendicular to the side of the tooth.

9. The method of producing a shaving gear which comprises employing a rotary face-mill cutting tool having blades which have a ribbed side surface which is parallel to the axis of the tool and a side cutting edge formed at the juncture of said side surface with the front faceof the blade, adjusting a previously toothed gear so that a side of a tooth of the gear is parallel to the axis of the tool, rotating the tool with the gear and while holding the blank stationary, and simultaneously producing a relative rotary movement between the tool andgear about an axis parallel to but offset from the cutter axis to produce a lateral feed movement between the tool and gear in a direction substantially perpendicular to the side of the tooth of the gear.

10. In a machine for grooving shaving gears,

a cutting tool having a side face provided with a plurality of alternate grooves and lands and a serrated side cutting edge formed at the juncture of said side face with the front face of the tool, means for moving the tool longitudinally across the face of a gear, means for relatively moving the tool into and out of operative engagement with the gear, means for producing alternately lateral feed and withdrawal movements between the tool and gear sidewise of a tooth of the gear when the tool is in engagement with the gear, and means for indexing the gear when the tool is out of engagement.

11. In a machine for grooving shaving gears, a face-mill cutting tool having blades with side surfaces which are provided with alternate grooves and lands extending from front to rear of the blades and a side cutting edge formed at the juncture of said side surface with the front face of the blades, means for rotating the tool with the gear, means for producing alternately lateral feed and withdrawal movements between the tool and gear sidewise of a tooth of the gear, and means for indexing the gear periodically when the tool is withdrawn.

12. In a machine for grooving shaving gears, a face-mill cutting tool having blades with serrated side cutting edges whose side surfaces are provided with alternate grooves and lands, means for rotating the tool with the gear, and means for producing a relative oscillatory movement between the tool and gear about an axis parallel to the axis of the tool to produce a lateral feed movement between the tool and gear sidewise of a tooth of the gear,

13. In a machine for grooving shaving gears, a face-mill cutting tool having blades which have serrated side cutting edges and side surfaces formed with alternate lands and grooves, means for rotating said tool with a gear, means for producing a relative oscillatory movement between the tool and gear about an axis parallel to the axis of the tool to produce alternately lateral movements of feed and withdrawal between the tool and gear in a direction substantially perpendicular to a side of a tooth of the gear, means for indexing the gear periodically when the tool isout of engagement with the gear, and means for displacingthe tool axially between cutting ofsucc'essive teeth of the gear so that the tool has a different axial position in cutting successive teeth of the gear.

14. The method of grooving the teeth of a shaving gearwhich comprises cutting grooves in the sides of different teeth of the gear by actuating a cutting tool in the lengthwise direction of a groove to be out while producing a relative lateral feed movement between the tool and gear to cut the groove to thedesired depth in a side of a tooth of the gear and withdrawing the tool from engagement with the gear and indexing the gear after the desired grooving operation has been performed on one tooth, and then bringing the tool back into operative position and repeating the operationto groove the new tooth, and shifting the position of the tool depthwise of the gear teeth between the cutting of grooves in different teeth of the gear so that said grooves are displaced depthwise relative to one another.

15. The method of grooving the teeth of a shaving gear which comprises cutting grooves in the sides of different teeth in the gear by rotating a face-mill gear cutter, having a plurality of cutting blades and which has cutting lands formed on the side faces of its blades, in engagement operation to groove the new tooth, and displac- .so that the grooves of different teeth will be diswith a gear while producing a relative lateral feed movement between the tool and gear to cut a groove of the desired depth into a side of a tooth of the gear, and withdrawing the tool from engagement with the gear and indexing the gear after the desired grooving operations have been performed on one tooth, then returning the tool into engagement with the gear and'repeating the ing the tool axially between the grooving of dif-' ferent teeth of the gear so that the grooves of diiferent teeth are displaced relative to one another in the direction of tooth depth.

16. The method of grooving the teeth'of a shaving gear which comprises cutting grooves in the sides of different teeth in the gear by rotating a face-mill gear cutter which has a cutting land formed on each cutting blade, in engagement with a gear while producing a relative feed movement between the tool and gear about an axis parallel to but ofiset from the cutter axis to cut a groove of the desired depth into a side. of a tooth of the gear, and withdrawing the cutter from engagement with the gear and indexing the gear after the desired grooving operations have been performed on one tooth, then returning the cutter into engagement with the gear and repeatrection of tooth depth.

17. The method of grooving the teeth of a shaving gear which comprises cutting grooves in the sides of different teeth of the gear by rotating a face-mill gear cutter which has a cutting land formed on each of its cutting blades, in engagement with a gear while producing a relative feed movement between the tool and gear about an axis parallel to the cutter axis and parallel to the cutting edges of said lands to cut a groove to the desired depth into a side of a tooth of the gear, and withdrawing the tool from engagement with the gear and indexing the gear after the desired grooving operationshave been performed on one tooth, then returning the tool into engagement with the gear and repeating the operations to groove a new tooth, and displacing the tool axially between cutting of difierent teeth of the gear so that the grooves cut in difierent teeth are displaced relative to one another in the direction of tooth depth.

18. A machine for grooving the teeth of shaving gears comprising a work support, a tool support, a tool movably mounted on the tool support, means for actuating the tool in the lengthwise direction of a groove to be cut, means for simultaneously producing a relative feed movement between the tool and gear to cut a groove of the desired depth in a side of the tooth of the gear,- means for periodically indexing the gear, and means for varying thedepthwise position of the tool relative to the gear between the cutting of grooves on different teethof the gear means for periodically indexing the gear, and

means for displacing the tool in the direction of tooth depth between the cutting of grooves on difierent teeth of the gear so that the grooves of diflerent teeth will be displaced relative to one another. v

20. A machine for grooving the teeth ,of a shaving gear comprising a work support, a tool support, a face-mill gear cutter journaled in said' tool support which has a cutting land formed on a side of each of its blades, means for rotating the cutter in engagement with a gear, means for simultaneously producing a relative lateral movement between the tool and gear to cut grooves of the desired depth inthe sides of the teeth of the gear, means for periodically indexing the gear, and means for displacing the cutter axially between the groovingof diiierent teeth of the gear so that the grooves cut therein will bedisplaced relative to one another.

-21. A machine for grooving the teeth of a shaving gear comprising a work support, a tool support, a face-mill gear cutter journaled in said the cutter in engagement with the gear, means for simultaneously producing a relative movement between the cutter and gearabout an axis parallel to thecutter axis to cut grooves of the desired depth in the sides of the teeth of the gear, means for periodically indexing the gear, and means for displacing the cutter axially be tween the grooving of difierent teeth of the gear so that the grooves cut therein will be displaced relative to one another. I

22. A machine for grooving the teeth of a shaving gear comprising avwork support, a tool support, a face-mill gear cutter journaled in said tool support which has acutti'ng land formed on a side of each of its blades, means for rotating the cutter in engagement with the gear, means for simultaneously producing a relative movement between the cutter and gear about an axis parallel to the cutter axis and parallel to the 

